This free pole size calculator helps electricians work out what size pole, post or strut is required for each job — in about ten seconds. It runs the sizing tables from the Service and Installation Rules of NSW (SIRNSW, July 2018), the document every Level 2 electrician in Sydney and across NSW sizes overhead service structures against.
Pick your service — 100 amp single-phase, 100 amp three-phase, 200 amp or 400 amp three-phase — and type the span of the service line. The calculator reads Table 3-8 to give you the required strength rating (S rating), normal tension and minimum breaking tension, then converts that S rating into real sizes: Grade 250 steel pipe pole diameters from Table 3-15, square timber post and timber strut sizes from Tables 3-9 and 3-10, and angle iron strut sizes in Grade 250 and Grade 300 from Tables 3-12 and 3-13. It also shows how deep the pole needs to go in the ground for poor, medium and good soil (Table 3-5), and produces a free branded PDF sizing report you can attach to the job file or send to your steel supplier.
Level 2 electricians (ASPs) use it to size private power poles for service upgrades, pole replacements, defect rectification and new overhead connections. Level 1 ASP crews use it as a fast sanity check on service structures before ordering materials. Level 3 ASP designers use it to confirm structure sizing assumptions in connection designs. It's equally handy for general electricians quoting jobs that involve a private pole, builders ordering temporary builder supply (TBS) poles, and homeowners who've been handed a defect notice on a leaning or rusted pole and want to understand what a compliant replacement looks like before getting quotes.
The calculator covers the five most common service structures in NSW: Grade 250 steel pipe poles, square timber posts, square timber struts, and angle iron struts in both Grade 250 and Grade 300. Any span is accepted — the tool automatically rounds up to the next row of Table 3-8 so the result is always on the safe side. It's a guide only, not engineering advice: always cross-check your printed copy of the Service and Installation Rules before certifying, and involve a structural engineer where clause 3.13 requires it.
This calculator is part of our free toolkit for sparkies: size the consumer mains running off the pole with our AS/NZS 3008 cable size calculator, look up any rule in plain English with the NSW Electrical Rules Clause Finder, or read the guide to using this tool on our resources page.
Cable Size & Voltage Drop Calculator (AS/NZS 3008) →NSW Electrical Rules Clause Finder →How to use the Pole & Strut Size Calculator (guide) →Need the pole supplied, installed and certified? High Demand Electrical's Level 2 ASP team installs and replaces private power poles across Sydney — call 0402 559 777 for a free quote.
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